Heat shielding the airboxes
Discussion
Completely unscientific, but looking at the position of the airboxes above the exhaust manifolds, it would appear that they're right in line for some serious heat-soak. While I'm sure that the volume of air being gulped through the boxes means that its not around long enough to pick up much heat, sitting 3" from a red hot manifold can't be ideal.
Does anyone think that covering the bottoms of the boxes with heat-shield matting would help? Perhaps going a little further and also making up a pair of aluminium plates to fit between the manifolds and the boxes.
Thoughts?
Also, as an aside, the concertia pipes from the air filter to the boxes don't look great for flow (zig-zag walls creating turbulence). Any meaningful benefit to swapping for flat walled hoses? (I'm guessing not).
Does anyone think that covering the bottoms of the boxes with heat-shield matting would help? Perhaps going a little further and also making up a pair of aluminium plates to fit between the manifolds and the boxes.
Thoughts?
Also, as an aside, the concertia pipes from the air filter to the boxes don't look great for flow (zig-zag walls creating turbulence). Any meaningful benefit to swapping for flat walled hoses? (I'm guessing not).
I seem to remember Trackcar saying he had lined the underside of the airboxes when he was trying out all the various induction mods.
Can't remember if he thought it made any worthwhile difference.
No idea about the concertina shape of the pipes but I think length does make a difference. Wasn't there a thread recently about it?
Can't remember if he thought it made any worthwhile difference.
No idea about the concertina shape of the pipes but I think length does make a difference. Wasn't there a thread recently about it?
A smooth wall hose would definitly make a difference, if its a noticeable one though I'm not sure. You can get silicon hoses from here which also would smarten up under the bonnet as well.
http://www.sfsperformance.co.uk/straight.asp
http://www.sfsperformance.co.uk/straight.asp
I'm not particularly chasing that last bhp point per se - the car saw 408 last time it was on Joolz's rollers, and to be honest it all gets pretty manic at full throttle and I'm not sure if I could really tell 5-10bhp either way - it's just things like this tend to bug me - a purity of design/ideal for purpose kind of thing.
I think I might get some heatshield matting, break out the laser thermometer and do some tests.
I would make up some smooth plastic primaries too, but they're too big for my pipe-bender, and using a combination of straight and right-angled bitsa would defeat the whole object.
I think I might get some heatshield matting, break out the laser thermometer and do some tests.
I would make up some smooth plastic primaries too, but they're too big for my pipe-bender, and using a combination of straight and right-angled bitsa would defeat the whole object.
Hi Neil .. Ive done the airbox lagging thing in the past, but to be honest it seems to make very little difference to what happens to the hp. As you say it's probably the air rushing in so fast that it doesnt pick up much heat anyway. The bottom of the airboxes are made in the honeycomb stuff that the doors and boots are made of so that must reduce the heat transfer a bit. The Rover V8 seems very sensitive to inlet air temps and once you start seeing those rise on the ecu its time to stop and let it cool down .. the cerb doesnt seem overly fussed on being worked on the dyno for ages (a very artificially heat-intense environment), the hp never seems to change from what I can tell. It's probably worth doing if youve got the boxes off one day but don't expect anything like a decent hp increase because of it.
As you seem to have tried most things, here's one for you:
Do you think there'd be any benefit to channelling inside the airboxes? Perhaps a vertical split at the intake end to channel half the incoming air to the farthest two cylinders, or perhaps something more technical. I remember reading somewhere about some folks making up a plenum for a homemade Efi system on an old ford crossflow, and the difference between a baffled and non-baffled box was night and day.
On the heat shield issue - I'm going to pick up some matting anyway, as I want to wrap my newly reconditioned starter for piece of mind, so I'll do the airboxes at the same time and get some before and after temperature readings and report back.
Do you think there'd be any benefit to channelling inside the airboxes? Perhaps a vertical split at the intake end to channel half the incoming air to the farthest two cylinders, or perhaps something more technical. I remember reading somewhere about some folks making up a plenum for a homemade Efi system on an old ford crossflow, and the difference between a baffled and non-baffled box was night and day.
On the heat shield issue - I'm going to pick up some matting anyway, as I want to wrap my newly reconditioned starter for piece of mind, so I'll do the airboxes at the same time and get some before and after temperature readings and report back.
Hi Neil,
I have just had my exhaust manifolds ceramic coated, this is supposed to drop the temp under the bonnet down dramatically, I have also had the bottom of the air boxes covered in heat shield, not sure how good it is, as the car as not on the road yet, will keep you informed.
I have just had my exhaust manifolds ceramic coated, this is supposed to drop the temp under the bonnet down dramatically, I have also had the bottom of the air boxes covered in heat shield, not sure how good it is, as the car as not on the road yet, will keep you informed.
Edited by cerb45 on Friday 18th January 19:00
Gassing Station | Cerbera | Top of Page | What's New | My Stuff